Relationship ofHearing Preservation of Patients with Neurofibromatosis Type 2 withTumor Maximum Standardized Uptake from the ¹¹C-MET PET/CT Images

Objectives: Preoperative hearing test results was an important index for evaluating hearing functional preservation in Neurofibromatosis Type 2 (NF2) patients with bilateral vestibular schwannomas (VS) who underwent surgery resection. The aim of this study was to investigate the utility of SUVmax on 11C-MET PET/CT in patients with NF2 to predict the change of hearing.

Methods: Thirty young NF2 patients in a prospective natural history (17 men, 13 women; median age, 21.7 years) with 53 measurable hearing ears was minored by brain ¹¹C-MET PET/CT and MRI imaging from 2015 to 2018. The hearing function was classified by the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria. Tumor maximum standardized uptake (SUVmax) was obtained from PET/CT images automatically . Cox regression were used to assess the association between PET/CT markers with hearing.

Results: Eighteen ears maintained effective hearing (Class A and B) ears while 35 ears hearing significant loss (Class C and D) among 53 ears during follow-up. The SUVmax was correlated significantly with hearing grades (P=0.002, rs=0.324). In comparison with those patients with low metabolic activity in ¹¹C-MET PET/CT findings (SUVmax<2.75), a significant decrease of hearing was discovered in patients with high metabolic activity in ¹¹C-MET PET/CT findings ( SUVmax>2.75) . The higher SUVmax was associated with hearing decrease on a univariate Cox model (hazard ratio = 0.433, P=0.002).

Conclusions: The SUVmax was related to the patient’s hearing in NF2, as an independent predictive factor of hearing loss in natural history.Key words Neurofibromatosis type 2, PET, Vestibular schwannoma, Hearing preservation